Magnetic closer



(No Model.) 2 Sheets-Sheet 1. v

' J. N. THOMAS. MAGNETIC CLOSER. No. 599,881. Patented Mar; 1, 1898.

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INV NTOI? (No Model.) 2 Sheets-Sheet 2.

' J. N. THOMAS.

MAGNETIC" CLOSER.

No.'599,881. Patented Mar. 1, 1898.

UNITED STATES PATENT OFFICE. Y

JOSEPH N. THOMAS, OF JOHNSTOWN, PENNSYLVANIA, ASSIGNOR TO THE JOHNSON COMPANY, OF LORAIN, OHIO.

MAGNETIC .C LOSER.

SPECIFICATION forming part of Letters Patent No. 599,881, dated March 1, 1898.

Application fil d October 19, 1897. Serial No. 655,658- (No model.)

- this specification.

My invention relates to magnets of that type which are carried by electric vehicles to actuate a current-conveyer placed between the bared working conductor and the source of supply. In railways in which traveling magnets of this character are used there is danger of the magnet-pole'acting to shortcircuit one of the bared conductor-contacts to the rails of a crossing track, because the trackrails are generally connected to the opposite side of the circuit to that with which the aforesaid contacts are connected. This shortcircuiting may be established either by small pieces of magnetic material being picked up by the magnet, so bringing the poles of the magnet into direct connection with a contact or crossing rail, or both, or it may be established by unevennesss of the track or poor adjustment of the position of the magnet, which might allow the latter to come into direct contact with the parts of the circuit men- .tioned. The object of my invention is to avoid this danger by providing a magnet which will have the substantially continuous magnetic fields, which are desirable, but which will at the same time be composed of electrically-disconnected sections.

Referring to the accompanying drawings, Figure 1 is a plan View, Fig. 2 a side view, and Fig. 3 a tranverse section, of a magnet embodying the features of my invention.

. Figs. 4: and 5 are enlargedsections showing the means I employ for the construction of the magnet-poles. Fig. 6 is a perspective View of a modified form of construction whichalso embodies the general principle of my invention. Fig. 7 is a sectional view of the same, and Fig. 8 is a section of one of the poles of the magnet.

The particular magnet which I have shown is made of a plurality of yokes A, surrounded by energizing-coils B, having their ends connected by pole-pieces in such a manner as to form one magnet having two longitudinal parallel poles.

In the preferred form of construction which I show in Figs. 1 to 5, inclusive, the lower ends of the cores A are secured by suitable countersunk screws 5 (see Fig. 3) to plates of magnetizable material, as a. a and 0. are plates of similar material which are secured to plates a by means of bolts dand e. A construction similar to this is employed throughout the length of the pole-piecethat is to say, there is an upper layer of plates a a a &c., and a lower layer of plates a a a*, 850., secured to the upper layer by means of bolts, as d and 6. Between the upper and lower set of plates is the insulation 0, such as sheet-rubber. As will be noted, this insulation not only is placed between the upper and lower plates, but its ends are brought upward or downward, as the case may be, so as to insulate adjacent plates of the same layer, such as a from a or a from a Ipreferably place this insulation so that the joints in the upper and lower layers will be staggered. The insulation between the different members of the upper layer is not absolutely essential.

Referring to Fig. 4, e is a tap-bolt which screws into the upper layer of plates, as a, and is insulated from the lower layer, as a, by a suitable insulating compound 6, cast about the bolt.

Referring to Fig. 5, dis a tap-bolt which screws into the lower layer of plates, as a, and is protected from the upper layer of plates, as a, by the molded insulating compound (1. It is of course obvious that I may, if desired, use the construction shown in Fig. 4 for all the fastenings. With this form of magnet it is clear that I entirely avoid the danger of short-circuitin g the railway system under the conditions which I have previously set forth. At the same time I do not weaken the magnetic field to any appreciable extent, for the magnetic lines are distributed over such a large surface area when passing through the insulator O that the loss is inappreciable.

On Sheet 2 of the drawings I illustrate another form which my invention may take. In this form I provide a plurality of channelirons A, connected by rivets'to continuous wooden blocks 0 and separated by suitable insulators C such as fiber or mica. Under some circumstances this form of magnet might be desirable, for it is Very simple and may be cheaply constructed. It has not, however, as good a magnetic path as the magnet shown on Sheet 1, and I therefore generally prefer to use the latter.

It is clear that I am not limited to the particular details described, for I believe that it is broadly new to provide a magnetic closer having a longitudinal pole which is substantially continuous magnetically, but discontinuous electrically, and it is my desire to claim this feature regardless of the particular details of construction by which it is obtained.

Having thus described myinvention, what I claim, and desire to protect by Letters Patent, is-

1. A magnetic closer having an extended pole adapted to supply a substantially continuous magnetic field throughout its length and composed of a plurality of sections insulated from each other.

2. A magnetic closer having a longitudinal pole adapted to supply a substantially continuous magnetic field throughout its length and composed of electrically-disconnected sections.

3. Amagnetic closercomprising a plurality of cores and energizing-coils for the same, in combination with continuous members secured to the ends of the cores and composed of aplurality of electrically-disconnected sections.

4:. A pole-piece for a magnetic closer composed of adjacent parallel layers, each layer being composed of a plurality of magnetizable members, the members of each layer and the adjacent members of different layers being insulated from each other.

5. An extended pole-piece for magnetic closers having a plurality of sections arranged in suffieiently close proximity to each other to provide a substantially continuous magnetic path, but separated by suitable insulating members.

6. An extended pole piece for magnetic closers, comprising the combination of an upper magnetizable layer contacting with the cores of the magnet, a center layer of insulating material, and a lower magnetizable layer made up of a plurality of sections separated by suitable insulation.

7. The extended pole piece herein described,comprisin g the upper and lower members, each composed of a plurality of iron plates separated by insulators, and the center layers composed of a sheet of rubber or other suitable insulating material.

8. In combination, the layer of iron plates a, a a &c., separated by suitable insulating material, the second layer of iron plates, a, a a, &c., similarly separated, the interposed sheet of insulating material, and insulated tap'bolts securing the whole together.

In testimony whereof I have affixed my signature in presence of two Witnesses.

J OSEPI'I N. THOMAS. lVitnesses:

JOHN II. KENNEDY, H. W. SMITH. 

